Decreased grip strength is associated with paraspinal muscular oxidative stress in female lumbar degenerative disease patients

We aimed to investigate the relationship between superoxide dismutase 2-related oxidative stress in the paraspinal muscles and spinal alignment, clinical skeletal muscle parameters, and mitochondrial function. Multifidus muscle samples from patients who underwent posterior lumbar surgery were analyzed. Patients with diseases affecting oxidative stress and spinal alignment were excluded. The superoxide dismutase 2 redox index was defined as the ratio of reactive oxygen species (superoxide) to antioxidant enzymes (superoxide dismutase 2) and was used as an index of oxidative stress. Patients were divided into two groups based on the superoxide dismutase 2 redox index. Spinal alignment, clinical skeletal muscle parameters, and succinic dehydrogenase (SDH) mean grayscale value were compared between the groups, with analyzes for both sexes. Multiple regression analyzes were used to adjust for the confounding effect of age on variables showing a significant difference between the two groups. Thirty-five patients with lumbar degenerative diseases were included. No significant differences were observed between the two groups for any of the parameters in males; however, females with a higher superoxide dismutase 2 redox index had greater lumbar lordosis, lower grip strength, and higher SDH mean grayscale value than those with a lower index. Multiple regression analyzes revealed that the superoxide dismutase 2 redox index was an independent explanatory variable for lumbar lordosis, grip strength, and SDH mean grayscale value in female patients. In conclusion, superoxide dismutase 2-related oxidative stress in the paraspinal muscles was associated with mitochondrial dysfunction and decreased grip strength in female lumbar degenerative disease patients.

Implications of DNA Methylation Classification in Diagnosing Ependymoma

BACKGROUND

Ependymoma is a central nervous system (CNS) tumor that arises from the ependymal cells of the brain's ventricles and spinal cord. The histopathology of ependymomas is indistinguishable regardless of the site of origin, and the prognosis varies. Recent studies have revealed that the development site and prognosis reflect the genetic background. In this study, we used genome-wide DNA methylation array analysis to investigate the epigenetic background of ependymomas from different locations treated at our hospital.

METHODS

Four cases of posterior fossa ependymomas and 11 cases of spinal ependymomas were analyzed.

RESULTS

DNA methylation profiling using the DKFZ methylation classifier showed that the methylation diagnoses of the 2 cases differed from the histopathological diagnoses, and 2 cases could not be classified. Tumor that spread from the brain to the spinal cord was molecularly distinguishable from other primary spinal tumors.

CONCLUSIONS

Although adding DNA methylation classification to conventional diagnostic methods may be helpful, the diagnosis in some cases remains undetermined. This may affect decision-making regarding treatment strategies and follow-up. Further investigations are required to improve the diagnostic accuracy of these tumors.

Advancements and Challenges in Robot-Assisted Bone Processing in Neurosurgical Procedures

OBJECTIVE

Practical applications of nerve decompression using neurosurgical robots remain unexplored. Our ongoing research and development initiatives, utilizing industrial robots, aim to establish a secure and efficient neurosurgical robotic system. The principal objective of this study was to automate bone grinding, which is a pivotal component of neurosurgical procedures.

METHODS

To achieve this goal, we integrated an endoscope system into a manipulator and conducted precision bone machining using a neurosurgical drill, recording the grinding resistance values across 3 axes. Our study encompassed 2 core tasks: linear grinding, such as laminectomy, and cylindrical grinding, such as foraminotomy, with each task yielding unique measurement data.

RESULTS

In linear grinding, we observed a proportional increase in grinding resistance values in the machining direction with acceleration. This observation suggests that 3-axis resistance measurements are a valuable tool for gauging and predicting deep cortical penetration. However, problems occurred in cylindrical grinding, and a significant error of 10% was detected. The analysis revealed that multiple factors, including the tool tip efficiency, machining speed, teaching methods, and deflection in the robot arm and jig joints, contributed to this error.

CONCLUSION

We successfully measured the resistance exerted on the tool tip during bone machining with a robotic arm across 3 axes. The resistance ranged from 3 to 8 Nm, with the measurement conducted at a processing speed approximately twice that of manual surgery performed by a surgeon. During the simulation of foraminotomy under endoscopic grinding conditions, we encountered a -10% error margin.

Diagnosis and Management of Tethered Cord Syndrome

Tethered cord syndrome is a condition in which the spinal cord is tethered by pathological structures such as a tight filum terminale, intradural lipomas with or without a connecting extradural component, intradural fibrous adhesions, diastematomyelia, and neural placode adhesions following closure of a myelomeningocele.It usually occurs in childhood and adolescence as the spine grows in length, but it can also develop in adulthood. Symptoms of tethered cord syndrome are slowly progressive and varied. Incorrect diagnosis and inappropriate treatment may be provided if the physician lacks knowledge and understanding of this disease.This chapter aims to describe the pathophysiology, syndromes, diagnostic imaging, surgical treatment, and prognosis of tethered cord syndrome to enhance the understanding of this condition.

Full Endoscopic Spine Surgery with Image-Guided Navigation System as "Hybrid Endoscopic Spine Surgery": A Narrative Review

Endoscopic surgery is adopted as a minimally invasive technique in several surgical fields. Endoscopic spine surgery (ESS) was performed initially for lumbar discectomy but is currently widely utilized for various pathologies. Similar to other endoscopic techniques, ESS has a steep learning curve that has recently been a topic of discussion. Image-guided navigation systems have been developed for spine surgery. Intraoperative computed tomography enables the use of an image-guided navigation system in ESS, which is a suitable approach for managing complex lesions. Full-ESS is currently being adopted for certain cervical pathologies, and the incorporation of an image-guided navigation system will soon enable surgery for other cervical pathologies.

Intramedullary Schwannoma of the Spinal Cord: A Nationwide Analysis by the Neurospinal Society of Japan

OBJECTIVE

This study was aimed to report the clinical characteristics of intramedullary schwannomas and discuss imaging findings and treatment strategies.

METHODS

The inclusion criterion was consecutive patients with intramedullary schwannomas who were surgically treated at 8 centers between 2009 and 2020. Clinical characteristics included age, sex, clinical presentation, disease duration, and follow-up period. The modified McCormick scale was used to compare the preoperative and postoperative conditions. Pre- and postoperative magnetic resonance images (MRI) of each case were analyzed.

RESULTS

The mean age of the total 11 patients at the operation was 50.2 years. The mean duration of the symptoms was 23 months, with limb paresthesia being the most common clinical presentation. The cervical spine was the most common localization level of the tumor in 6 cases. The mean follow-up duration was 49.4 months. Gross total resection (GTR) and subtotal resection (STR) was achieved in 9 and 2 cases, respectively. According to the modified McCormick scale at 6 months postoperatively, 7 cases (63.6%) had improved and 4 cases (36.3%) had unchanged grades. Typical MRI findings of the intramedullary schwannoma included ring-like enhancement, syringomyelia, cystic formation, intramedullary edema, and hemosiderin deposition. Gadolinium enhancement was homogenous in 8 cases (72.7%). The tumor margins were well demarcated in all cases.

CONCLUSION

Intramedullary schwannoma should be considered when sharp margins and well-enhanced tumors are present at the cervical spine level and the initial symptoms are relatively mild, such as dysesthesia. When GTR cannot be achieved, STR for tumor decompression is recommended.

Comparison of the Degree of Expanded Spinal Canal Area between the Hinge-Side Area and the Open-Side Area in Cervical Open-Door Laminoplasty

Background

There have been reports on the significant canal cross-sectional area (CSA) expansion difference between pre- and post-operation, but no comparison of CSA expansion between the hinge-side area (Area H) and the open-side area (Area O) has been reported. This study aimed to measure the spinal CSA expansion between Area H and Area O retrospectively after open-door laminoplasty using new titanium spacers and evaluated this common decompression procedure's effectiveness.

Materials and Methods

This study included 27 patients diagnosed with cervical spondylotic radiculopathy or myelopathy, ossification of the posterior longitudinal ligament, and developmental canal stenosis from February 2021 to October 2022. The CSA difference between pre- and post-cervical laminoplasty (C4-C6 levels) was measured with cervical transverse computed tomography scan images. The CSA difference in Area H and Area O between pre- and post-laminoplasty was similarly calculated.

Results

The spinal canal areas of each segment after open-door laminoplasty were significantly enlarged (P < 0.05). Area O was also significantly enlarged compared to that of Area H (P < 0.05).

Conclusion

Area O was more enlarged than Area H, and both sides were statistically enlarged after open-door laminoplasty.

Elimination of Lumbar Plexus Injury by Changing the Entry Point and Traction Direction of the Psoas Major Muscle in Transpsoas Lateral Lumbar Spine Surgery

Background and Objectives: The lateral approach is commonly used for anterior column reconstruction, indirect decompression, and fusion in patients with lumbar degenerative diseases and spinal deformities. However, intraoperative lumbar plexus injury may occur. This is a retrospective comparative study to investigate and compare neurological complications between the conventional lateral approach and a modified lateral approach at L4/5. Materials and Methods: Patients with a lumbar degenerative disease requiring single-level intervertebral fusion at L4/5 were included and categorized into group X and group A. Patients in group X underwent conventional extreme lateral interbody fusion, while those in group A underwent a modified surgical procedure that included splitting of the anterior third of the psoas muscle, which was dilated by the retractor on the anterior third of the intervertebral disc. The incidence of lumbar plexus injury, defined as a decrease of ≥1 grade on manual muscle testing of hip flexors and knee extensors and sensory impairment of the thigh for ≥3 weeks, on the approach side, was investigated. Results: Each group comprised 50 patients. No significant between-group differences in age, sex, body mass index, and approach side were observed. There was a significant between-group difference in intraoperative neuromonitoring stimulation value (13.1 ± 5.4 mA in group X vs. 18.5 ± 2.3 mA in group A, p < 0.001). The incidence of neurological complications was significantly higher in group X than in group A (10.0% vs. 0.0%, respectively, p < 0.05). Conclusions: In our modified procedure, the anterior third of the psoas muscle was entered and split, and the intervertebral disc could be reached without damaging the lumbar plexus. When performing lumbar surgery using the lateral approach, lumbar plexus injury can be avoided by following surgical indication criteria based on the location of the lumbar plexus with respect to the psoas muscle and changing the transpsoas approach to the intervertebral disc.

Perioperative Management for Full-Endoscopic Lumbar Discectomy: Consideration From the Perspective of Preventing Complication

In recent years, full-endoscopic discectomy (FED) has expanded its range of indications with the development of devices and various techniques. The advantage of FED over conventional surgery is that it is a minimally invasive procedure. However, intraoperative and postoperative precautions must be taken to prevent complications. It is necessary to avoid complications that could compromise the outcome of the procedure. Effective perioperative management is necessary to avoid complications; however, there is no set view for perioperative management in FED. In this study, we perform a literature review to examine the effectiveness of perioperative management methods for FED. The key to ensuring the efficacy and minimal invasiveness of FED is prevention of complications. Based on the result and literature review, we believe that the most manageable postoperative management after FED is prevention of recurrent disc herniation and hematoma formation. A drain should be placed to prevent postoperative hematoma formation. It is advisable to evaluate the patient’s symptoms and monitor C-reactive protein and erythrocyte sedimentation rate levels during the first week after surgery. Postoperative antibiotics were administered for 1 day.

Three-dimensional morphological analysis of the thoracic pedicle and related radiographic factors in adolescent idiopathic scoliosis

Background

This study aimed to investigate the laterality of the pedicle morphology at the apical vertebra (AV) level and identify the radiographic factors associated with the laterality ratio of the pedicle morphology at the AV level in patients with adolescent idiopathic scoliosis (AIS).

Methods

Overall, 684 pedicles in 57 AIS patients aged 10–20 years, who underwent preoperative computed tomography (CT) and had Lenke type 1 or 2 with right convex main thoracic curves (MTC), were evaluated. Pedicle diameters of the MTC were assessed. We defined and compared the region containing two vertebrae adjacent to the AV (APEX±1) and the region containing two vertebrae adjacent to the neutral vertebra. We analyzed the pedicle diameter and laterality ratio of APEX±1 and performed multiple linear regression analysis to identify the radiographic factors associated with the laterality of the pedicle diameter.

Results

On the concave side of APEX±1, the pedicles of 15 patients (26.3%) did not accept a 4-mm-diameter pedicle screw (PS), even with 25% cortical bone width expansion. Laterality ratio differences in the pedicle diameters of the cortical bone width in APEX±1 were large in patients with more proximal AV level (p < 0.001) and smaller apical vertebral rotation (AVR) (p = 0.029).

Conclusions

Preoperative planning to accurately select and insert the PS in AIS should be based on the anatomical limitations in APEX±1, AV level, and AVR degree. In APEX±1, the correlation between AVR and the laterality ratio of the pedicle diameter may be useful for pathoetiological interpretation of the AIS deformity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05799-4.

O-207 Incidence of Y chromosome microdeletions and microdissection testicular sperm extraction (micro TESE) in patients with Japanese azoospermic patients

Study question

What is the frequency of azoospermia factor (AZF) microdeletions and sperm retrieval rate (SRR) by micro TESE in patients with these deletions?

Summary answer

AZFc is most frequent of Y chromosome microdeletions and a predictor of micro TESE outcome in Japanese azoospermic men.

What is known already

After Klinefelter syndrome, Y chromosome microdeletions are the second most frequent genetic cause of male infertility, with a prevalence of 2%-10% in non-obstructive azoospermia (NOA) and three spermatogenesis loci in the Y chromosome long arm (Yq11) have been classified as AZFa, AZFb, and AZFc. The classical correlation of histopathology phenotypes with these three microdeletions comprises of complete absence of germ cells (Sertoli cell-only syndrome) in patients with AZFa microdeletions, maturation arrest of meiosis in patients with AZFb microdeletions, and hypospermatogenesis in patients with AZFc microdeletions, however, individual variation in the extent of deletions has led to various spermatogenic phenotypes.

Study design, size, duration

We performed a retrospective study based on two reproduction centers in Japan and evaluated 1373 azoospermic patients in our clinics between September 2013 and December 2021. We investigated the frequency of AZF microdeletions and SRR by micro TESE in patients with these microdeletions and therefore aimed to evaluate the correlation between AZF microdeletions and micro TESE results.

Participants/materials, setting, methods

A total of 1373 azoospermic were enrolled. After the diagnosis of azoospermia, karyotype analysis and detection of Y chromosome microdeletions were performed on peripheral blood lymphocytes of these patients. Y chromosome microdeletions in AZFa, AZFb, and AZFc regions were detected using Promega Y Chromosome AZF Analysis System version 2.0 (Promega Co.). Twenty sequence-tagged sites within the AZF region of Yq11 and the sex-determining region Y gene were targeted for polymerase chain reaction (PCR) amplification.

Main results and the role of chance

One hundred and fifty-two AZF microdeletions (11.1%) were detected in the azoospermic patients. The most common deleted region was AZFc (60 cases, 4.4%). Among the patients, 17 (1.2%), 1 (0.1%), 42 (3.1%), 13 (1.0%), and 6 (0.5%) had AZFa, AZFa+b, AZFb+c, AZFb, and AZFa+b+c microdeletions, respectively. When the cases were grouped according to causes of infertility that could be detected, no Y chromosome microdeletions were detected in some groups (cases with Klinefelter Syndrome, hypogonadotropic hypogonadism, congenital absence of vas deferens, and 47, XYY karyotype). Fifty-three azoospermic men with AZFc microdeletions underwent micro TESE, and spermatozoa were detected in 88.7% (47/53) of these men. In contrast, we detected spermatozoa in only 20.4% (109/534) of the azoospermic men without AZF microdeletions. The SRR was much higher in patients with AZFc microdeletions than that of patients without AZF deletions. Although three azoospermic men with AZFb+c microdeletions had also undergone micro TESE following patient request, we did not retrieve spermatozoa.

Limitations, reasons for caution

We excluded post chemotherapy NOA showing 46, XX and AZFa+b+c deletions post bone marrow transplantation from female donor. Additionally, we did not detect AZFc partial deletion including gr/gr deletion. The cohort size of this study is not small, however, our screened population of infertile men may be biased.

Wider implications of the findings

NOA patients with AZFc microdeletions had a high percentage of successful sperm retrieval by micro TESE. Our study emphasizes that diagnosis of Y chromosome microdeletions is critical for preconception genetic counseling and provides clinically valuable prognostic information to couples considering surgical sperm retrieval.

Trial registration number

None

O-130 Reproductive outcomes of normal ovarian reserve patients after progestin-primed ovarian stimulation with chlormadinone acetate vs GnRH antagonist: A retrospective study with inverse-probability-of-treatment weighting

Study question

To evaluate the effectiveness of chlormadinone acetate (CMA) for preventing premature LH surge in patients with normal ovarian reserve compared to cetrorelix.

Summary answer

In progestin-primed ovarian stimulation (PPOS) than GnRH antagonist (GnRH-ant), the incidence of premature LH surge was significantly lower, without significant difference in oocyte maturation rate.

What is known already

The GnRH-ant protocol is one of the conventional protocols which has some disadvantages including increased premature LH surge rate and cancelation rate. In recent years, the PPOS protocol has attracted attention as a new ovarian stimulation using progestin as an alternative to GnRH analog for suppressing a premature LH surge, however its efficacy is still controversial. In addition, many studies have investigated the reproductive outcomes of PPOS using medroxy-progesterone acetate or dydrogesterone; however, there are few reports of CMA, an oral progestin, which is inexpensive and widely used in Japan.

Study design, size, duration

This retrospective cohort study was performed in a reproduction center between March 2018 and October 2020 which included 977 Japanese patients with normal ovarian reserve undergoing PPOS with CMA (n = 299), or GnRH antagonist (GnRH-ant) with cetrorelix (n = 608) in their first IVF cycle at the reproduction center. In subgroup analysis, pregnancy outcomes after frozen embryo transfers (FET) between PPOS (n = 284) and GnRH-ant (n = 579) were also compared.

Participants/materials, setting, methods

The inclusion criteria were patients aged &lt; 40 years and AMH ≧ 1.1 ng/mL, who underwent autologous oocyte retrieval in their first IVF cycle with freeze-all strategy. The primary outcome was the incidence of premature LH surge, the secondary outcomes was oocyte maturation rate. To reduce the impact of treatment bias and potential confounding factors, we conducted logistic regression models with inverse-probability-of-treatment weighting (IPTW).

Main results and the role of chance

After IPTW, baseline clinical data were well-balanced between the two groups, including age, AMH, BMI, the duration, type, and cause of infertility, antral follicle count, the history of recurrent spontaneous abortion, and previous IVF attempts. The premature LH surge rate was significantly lower with PPOS (3.1%) compared to GnRH-ant (20.1%) (odds ratio, 0.21; 95% confidence interval, 0.11–0.36). No significant differences were found in total gonadotropin dose (2400IU for PPOS vs 2400IU for GnRH-ant, p = 0.136), the number of oocyte retrieval (n = 15 vs n = 15, p = 0.484), oocyte maturation rate (78.8% vs 77.8%, p = 0.275), fertilization rate (73.0% vs 72.0%, p = 0.412), viable embryo rate per oocyte retrieval (40% vs 40%, p = 0.890), and good quality blastocyst rate (72.0% vs 69.6%, p = 0.092). However, the good quality day-3 embryo rate was significantly lower with PPOS (37.2% vs 49.1%, p &lt; 0.05). There were no differences in the incidence of moderate-to-severe OHSS (0.3% vs 0.7%, p = 0.481). In FET cycles, the pregnancy outcomes, such as implantation rate (43.1 % vs 51.9 %, p = 0.013) and clinical pregnancy rate (46.5% vs 54.7%, p = 0.027) were significantly lower with PPOS, however, no significant differences were found in ongoing pregnancy rate (75.6% vs 80.5%, p = 0.325), and live birth rate (72.4% vs 79.5 %, p = 0.142).

Limitations, reasons for caution

This was a retrospective cohort study conducted in a single center. The participants in this study were limited to Japanese ethnicity. The results need to be validated across different centers and other ethnicities.

Wider implications of the findings

This is the first report assessing the reproductive outcomes on PPOS using CMA, widely used in Japan. The PPOS with CMA significantly suppressed the premature LH surge rate compared to GnRH-ant protocol, without decrease in oocyte maturation rate.

Trial registration number

N/A

Anatomy of the L5 nerve root in the pelvis for safe sacral screw placement: a cadaveric study

OBJECTIVE

Previous reports have focused on the complications of L5 nerve root injury caused by anterolateral misplacement of the S1 pedicle screws. Anatomical knowledge of the L5 nerve root in the pelvis is essential for safe and effective placement of the sacral screw. This cadaveric study aimed to investigate the course of the L5 nerve root in the pelvis and to clarify a safe zone for inserting the sacral screw.

METHODS

Fifty-four L5 nerve roots located bilaterally in 27 formalin-fixed cadavers were studied. The ventral rami of the L5 nerve roots were dissected along their courses from the intervertebral foramina to the lesser pelvis. The running angles of the L5 nerve roots from the centerline were measured in the coronal plane. In addition, the distances from the ala of the sacrum to the L5 nerve roots were measured in the sagittal plane.

RESULTS

The authors found that the running angles of the L5 nerve roots changed at the most anterior surface of the ala of the sacrum. The angles of the bilateral L5 nerve roots from the right and left L5 intervertebral foramina to their inflection points were 13.77° ± 5.01° and 14.65° ± 4.71°, respectively. The angles of the bilateral L5 nerve roots from the right and left inflection points to the lesser pelvis were 19.66° ± 6.40° and 20.58° ± 5.78°, respectively. There were no significant differences between the angles measured in the right and left nerve roots. The majority of the L5 nerves coursed outward after changing their angles at the inflection point. The distances from the ala of the sacrum to the L5 nerve roots in the sagittal plane were less than 1 mm in all cases, which indicated that the L5 nerve roots were positioned close to the ala of the sacrum and had poor mobility.

CONCLUSIONS

All of the L5 nerve roots coursed outward after exiting the intervertebral foramina and never inward. To prevent iatrogenic L5 nerve root injury, surgeons should insert the S1 pedicle screw medially with an angle > 0° toward the inside of the S1 anterior foramina and the sacral alar screw laterally with an angle > 30°.

Cervical Extradural Arteriovenous Fistula without Intradural Drainage Successfully Treated with Endovascular Treatment Using Both Transvenous and Transarterial Approach: Case Report and Review of Literatures

The classification of spinal extradural arteriovenous fistulas (AVFs) was reported based on a case series treated by microsurgery in 2009 and endovascular interventions in 2011. The present report describes a patient with extradural AVFs at the cervical spine manifesting gradual progressive radiculomyelopathy of bilateral upper extremities. Magnetic resonance imaging (MRI) revealed a mass sign from C1 to C4 at the right ventral side and the spinal cord was deviated to the left and indicated as a flow void sign. Diagnostic angiography revealed an extradural AVFs located at the C1-C4 level that was supplied by bilateral radicular artery from the vertebral artery (VA) and right ascending cervical artery (ACA). The shunting points were recognized multiply at C2/3 and C3/4 levels on the right. The transvenous embolization to the enlarged extradural venous plexus around the shunting points via right hypoglossal canal and the transarterial embolization against multi-feeders of the branch of left radicular artery, right ACA achieved complete occlusion of the lesions. His symptom was gradually recovered, and angiography performed 2 weeks after embolization showed no recurrence. When the arteriovenous shunts in the upper cervical spine were high flow shunts, transvenous approach via the hypoglossal canal might be one option for the treatment of spinal extradural AVFs.

[How to Treat Osteoporotic Vertebral Fracture?]

In very elderly patients with low back pain, we must consider the possibility of osteoporotic vertebral fracture (OVF). In most patients with OVF, improvement can be observed without surgical intervention. However, even after providing the best possible conservative treatment, symptom recovery is not observed in some patients, and such patients experience delayed neurological deficits due to neural compression with the proceeding deformity of the vertebral body. Moreover, it is well known that once patients have OVF, the risk of another osteoporotic fracture in them increases. The clinical course of such patients eventually results in the loss of healthy life and increased mortality. Therefore, we should initiate medical treatment for osteoporosis at the earliest possible when OVF is detected in a patient. Patients who remain symptomatic even after undergoing adequate conservative therapy are candidates for balloon kyphoplasty. However, this minimally invasive surgery has some pitfalls. Furthermore, occasionally, we have to select instrumentation surgery for patients with delayed neurological deficits. In this "super-aged society," neurosurgeons also encounter patients with OVF not only in surgical situations but also in outpatient clinics. Thus, we should be aware about the clinical options for the management of osteoporosis.

[Posterior Lumbar Decompression:Variations and Pitfalls]

Lumbar canal stenosis is the most common pathological condition causing spinal degeneration. Symptomatic patients who fail conservative treatment are considered candidates for surgical treatment. Many types of minimally invasive procedures for lumbar decompression have been proposed, most of which are effective and have shown good long-term results. However, in special cases, a second operation may be needed for spondylolisthesis caused by degeneration of the same segment. Two major minimally invasive approaches are available for bilateral decompression of lumbar canal stenosis: unilateral approach and midline approach. The unilateral approach is used to preserve midline structures, the contralateral facet joint, and the contralateral paravertebral muscle. The midline approach is used to preserve the left and right facet joints and the enthesis of the paravertebral muscle. These two approaches are suitable for specific situations based on their own concepts. Nevertheless, it is important to understand the advantages and disadvantages of each procedure. In this article, the varieties of lumbar decompressive methods and the pitfalls of decompression procedures will be discussed.

Cervical endplate bone density distribution measured by CT osteoabsorptiometry and direct comparison with mechanical properties of the endplate

PURPOSE

Intervertebral device subsidence is one of the complications of anterior cervical discectomy and fusion. The biomechanical properties of vertebral bony endplate may be related to device subsidence. The aim of this study is to measure the cervical endplate bone density distribution using a novel 3D measurement method.

METHODS

Eight human cadaver cervical spines were obtained and levels C3-C7 were dissected and CT scanned. Three-dimensional (3D) CT model was created with the same 3D coordinates of the original DICOM dataset. The regional strength and stiffness of the endplate were determined by indentation testing. The indentation points were recorded by a photograph and the location of the indentation points was projected to the 3D CT model. Three-dimensional coordinates of the indentation point was obtained in the 3D space determined by the DICOM dataset. The area underneath the indentation point was calculated by a trilinear interpolation method directly. Data in HU and correlations with the indentation strength and stiffness were analysed.

RESULTS

A positive correlation was found between HU and strength (r = 0.52) and between HU and stiffness (r = 0.41). Overall, mechanical strength and stiffness and HU in the superior endplate of the caudal vertebra were lower than those in the inferior endplate of the cranial vertebra in the same intervertebral disc.

CONCLUSIONS

The mechanical properties and the HU were found to be significantly correlated, which employed a novel 3D HU measurement method, thus demonstrating potential to predict cervical endplate failure risk in a clinical setting.

TRENDS IN THE PREVALENCE OF FRAILTY IN JAPAN: A META-ANALYSIS FROM THE ILSA-J

OBJECTIVE

To examine whether age-specific prevalence of frailty in Japan changed between 2012 and 2017.

DESIGN

This study performed meta-analyses of data collected from 2012 to 2017 using the Integrated Longitudinal Studies on Aging in Japan (ILSA-J), a collection of representative Japanese cohort studies.

SETTING

The ILSA-J studies were conducted on community-living older adults.

PARTICIPANTS

ILSA-J studies were considered eligible for analysis if they assessed physical frailty status and presence of frailty in the sample. Seven studies were analyzed for 2012 (±1 year; n = 10312) and eight studies were analyzed for 2017 (±1 year; n = 7010). Five studies were analyzed for both 2012 and 2017.

MEASUREMENTS

The study assessed the prevalence of frailty and frailty status according to 5 criteria: slowness, weakness, low activity, exhaustion, and weight loss.

RESULTS

The overall prevalence of physical frailty was 7.0% in 2012 and 5.3% in 2017. The prevalence of frailty, especially in people 70 years and older, tended to decrease in 2017 compared to 2012. Slight decreases were found in the prevalence of frailty subitems including weight loss, slowness, exhaustion, and low activity between 2012 and 2017, but change in the prevalence of weakness was weaker than other components.

CONCLUSIONS

The prevalence of physical frailty decreased from 2012 to 2017. There are age- and gender-related variations in the decrease of each component of frailty.

Correlation of left atrial strain with left ventricular end-diastolic pressure in patients with coronary artery disease and preserved left ventricular ejection faction

Funding Acknowledgements

Type of funding sources: None.

Background

Elevated left ventricular (LV) filling pressures are the main physiologic consequence of LV diastolic dysfunction. Left atrial (LA) strain was recently found useful to predict elevated LV filling pressures noninvasively. However, there are few reports on the role of LA strain when predicting LV filling pressure in patients with coronary artery disease (CAD). The aim of this study was to explore the correlation between LA strain and LV end-diastolic pressure (LVEDP) in patients with CAD and preserved LV ejection fraction.

Methods

Fifty-four patients with stable CAD were enrolled. Global atrial longitudinal strain was measured by averaging all atrial segments. Resorvoir (S-LAs), conduit (S-LAe), and contractile (S-LAa) phase strain were obtained. LVEDP was invasively obtained by left heart catheterization.

Results

Patients were divided into two groups: elevated LVEDP group (LVEDP &gt; 15mmHg group: n = 23) and normal LVEDP group (LVEDP ≤ 15mmHg group: n = 31). Elevated LVEDP group showed significantly decreased S-LAs and S-LAa (S-LAs: 21.3 ± 7.2% vs. 27.5 ± 7.8%, p &lt; 0.005; S-LAa: 9.7 ± 3.3% vs. 14.6 ± 3.4%, p &lt; 0.0001). However, E/Ea and S-LAe were not significantly different between the two groups. LVEDP significantly correlated with S-LAa (r=-0.596, p &lt; 0.0001) and S-LAs (r=-0.431, p &lt; 0.001). Receiver operating characteristics curve analysis showed that S-LAa could predict elevated LVEDP (AUC = 0.84) and a cut-off value of S-LAa &lt; 11.6% was able to most accurately identify patients with elevated LVEDP.

Conclusions

LA strain, especially S-LAa, provided additional diagnostic value for the noninvasive assessment of LV filling pressure in CAD patients with preserved LV ejection fraction.

[Management of Spinal Disorders in Parkinson's Disease]

Parkinson's disease(PD)is a degenerative disorder of the central nervous system. Its cardinal features are resting tremor, rigidity, bradykinesia, and postural instability. Several years after disease onset, many patients with PD exhibit postural deformities, including camptocormia, Pisa syndrome, and dropped head syndrome, which can lead to spinal deformities. In addition, spinal degenerative disorders are frequently associated with PD and can further impact the patients' quality of life. Current evidence suggests a multifactorial etiology for postural deformities and spinal degenerative disorders in PD, which includes abnormal stress on the spine(biomechanical factors), postural instability and impairment of postural compensation(physiological factors), and imbalance of dopaminergic signals(pharmacological factors). The relative contribution of these factors varies between patients and across symptoms. Consequently, neurologists have difficulty treating these axial problems. Moreover, many studies have reported poor outcomes and high complication rates of spinal surgery in patients with PD, which embarrasses spinal surgeons. An improved understanding of the mechanisms underlying spinal problems in PD might ultimately lead to more effective management of these disabling complications.

Fluid Lubrication and Cooling Effects in Diamond Grinding of Human Iliac Bone

Background and Objectives: Although there have been research on bone cutting, there have been few research on bone grinding. This study reports the measurement results of the experimental system that simulated partial laminectomy in microscopic spine surgery. The purpose of this study was to examine the fluid lubrication and cooling in bone grinding, histological characteristics of workpieces, and differences in grinding between manual and milling machines. Materials and Methods: Thiel-fixed human iliac bones were used as workpieces. A neurosurgical microdrill was used as a drill system. The workpieces were fixed to a 4-component piezo-electric dynamometer and fixtures, which was used to measure the triaxial power during bone grinding. Grinding tasks were performed by manual activity and a small milling machine with or without water. Results: In bone grinding with 4-mm diameter diamond burs and water, reduction in the number of sudden increases in grinding resistance and cooling effect of over 100 °C were confirmed. Conclusion: Manual grinding may enable the control of the grinding speed and cutting depth while giving top priority to uniform torque on the work piece applied by tools. Observing the drill tip using a triaxial dynamometer in the quantification of surgery may provide useful data for the development of safety mechanisms to prevent a sudden deviation of the drill tip.

Association between Oral Frailty and Dietary Variety among Community-Dwelling Older Persons: A Cross-Sectional Study

OBJECTIVE

To examine the association between the severity of oral frailty (OF), which is one of the comprehensive oral functions evaluated, and dietary variety in community-dwelling older persons.

DESIGN

Cross-sectional study.

SETTING

Community-based.

PARTICIPANTS

A total of 769 community-dwelling older persons aged 65 and over.

INTERVENTIONS

We examined basic demographic information, functional status, cognitive status, depressive symptoms, medical history, and oral functions of the participants.

MEASUREMENTS

OF was defined by 1-2 and 3 or more of 6 items of oral function evaluation in the pre-oral frailty and oral frailty groups, respectively. Dietary variety was assessed using the dietary variety score (DVS). The participants were categorized into 3 groups for evaluation: those with a low score (0-2), medium score (3-5), and high score (≥6). Ordinal logistic regression analysis was performed to examine the association between OF and DVS.

RESULTS

The rate of OF in the participants was 21.6%, and its severity was significantly associated with DVS after adjusting for potential confounders (Pre-OF; adjusted odds ratio [OR] = 1.687, 95% confidence interval [CI] = 1.219-2.335, OF; adjusted OR = 2.857, 95% CI = 1.489-5.484).

CONCLUSION

The severity of OF was significantly associated with DVS in community-dwelling older persons. This suggests that DVS may be useful in understanding the effects of OF on the nutritional status. Further longitudinal studies are needed to elucidate the association between OF and DVS.

Anterior Spinal Fusion Using Autologous Bone Grafting via the Lateral Approach with Posterior Short-Range Instrumentation for Lumbar Pyogenic Spondylitis with Vertebral Bone Destruction Enables Early Ambulation and Prevents Spinal Deformity

Introduction

Pyogenic spondylitis of the lumbar spine markedly decreases the ability to perform activities of daily living and causes severe low back pain. The challenge is to improve low back pain and activities of daily living performance earlier and prevent post-infection sequelae, and conservative treatment with antibiotics is the mainstay of treatment.

Methods

In the present study, patients who were unable to walk following lumbar pyogenic spondylitis even in the subacute phase after successful infection control, showing bone defects expanding from endplate to vertebral body in CT, were treated with posterior percutaneous short-range instrumentation and anterior autogenous bone grafting (group S, n = 10) or with conservative treatment alone (group C, n = 10). Acute cases of absolute surgical indication with paralytic symptoms and mild cases who could walk by antibiotics administration were excluded. The two groups were compared regarding the post-treatment change in C-reactive protein level, duration of bed rest, and post-infection local spinal deformities (local scoliosis angle in the coronal plane and local kyphosis angle in the sagittal plane).

Results

Compared with group C, group S took a significantly shorter time for the C-reactive protein level to return to normal and required a significantly shorter duration of bed rest. Furthermore, surgery prevented the formation of kyphosis and scoliosis, while group C developed local kyphosis.

Conclusions

The minimally invasive surgical method of posterior percutaneous short-range instrumentation and anterior autogenous bone grafting effectively enables early control of pain and maintenance of locomotive function and prevents spinal deformity in patients with lumbar pyogenic spondylitis in the subacute phase with advanced vertebral bone destruction.

Localization of the Lumbar Plexus in the Psoas Muscle: Considerations for Avoiding Lumbar Plexus Injury during the Transpsoas Approach

Introduction

Transpsoas lumbar spine surgery is minimally invasive and has very good corrective effects. However, approach-side nerve complications delay post-operative rehabilitation. We anatomically investigated the localization of the lumbar plexus running in the psoas muscle.

Methods

We examined 27 formalin-fixed cadavers. The left-sided psoas muscle was extracted and cut parallel to the intervertebral disc at the L2/3, L3/4, and L4/5 disc levels. Using digitized photographs, we calculated the ratio of the distance from the front edge of the psoas muscle to the center of the lumbar plexus in the anteroposterior diameter of the psoas muscle (%). Then, we calculated the ratio of the distance from the lateral edge of the psoas muscle to the center of the lumbar plexus in the lateral diameter of the psoas muscle (%).

Results

The anterior-posterior lumbar plexus localization was 74.5 at L2/3, 74.7 at L3/4, and 81.2 at L4/5. There was a significant difference between L2/3 and L4/5 and between L3/4 and L4/5, but not between L2/3 and L3/4 (P=0.02, 0.01, and 0.94, respectively). The lateral and medial lumbar plexus localization was 85.4 at L2/3, 83.9 at L3/4, and 77.7 at L4/5. There was a significant difference between L2/3 and L4/5 and between L3/4 and L4/5, but not between L2/3 and L3/4 (P=0.01, 0.04, and 0.41, respectively).

Conclusions

The lumbar plexus was localized in the posterior one-third and medial one-third of the psoas muscle and moved to a posterolateral location at L4/5. To avoid neuropathy, consider the psoas muscle's position relative to that of the intervertebral disc. It is essential to understand lumbar plexus localization in the psoas muscle when looking directly at this muscle to enter the pricking point or route with a lower risk of nerve damage.